package server

import (
	"net/http"
	"strings"

	"send/internal/auth"
	"send/internal/store"
)

// handleDelete removes an object early. Three credentials are accepted: the
// delete token handed to the uploader, the token that owns the object, and any
// admin token.
//
// There is only one delete route, and it is a POST, so the success page's plain
// form works with scripting disabled and no second code path is needed.
func (s *Server) handleDelete(w http.ResponseWriter, r *http.Request) {
	id, err := store.CleanID(r.PathValue("id"))
	if err != nil {
		s.fail(w, r, http.StatusNotFound, "No such file.")
		return
	}
	m, err := s.store.Get(id, s.now())
	if err != nil {
		s.fail(w, r, http.StatusNotFound, "No such file.")
		return
	}

	secret := bearer(r)
	if secret == "" {
		// A small form post; the 4 KiB cap keeps this from being a way to
		// stream a body into memory.
		r.Body = http.MaxBytesReader(w, r.Body, maxFieldBytes)
		if err := r.ParseForm(); err == nil {
			secret = strings.TrimSpace(r.PostFormValue("token"))
		}
	}
	if secret == "" {
		s.fail(w, r, http.StatusUnauthorized, "A delete token or an owning token is required.")
		return
	}

	if !s.mayDelete(m, secret) {
		s.fail(w, r, http.StatusForbidden, "That token cannot delete this file.")
		return
	}
	if err := s.store.Delete(id); err != nil {
		s.log.Error("deleting object", "id", id, "err", err)
		s.fail(w, r, http.StatusInternalServerError, "Could not delete the file.")
		return
	}
	s.log.Info("deleted", "id", id, "ip", clientIP(r, s.cfg))

	if wantsJSON(r) {
		writeJSON(w, http.StatusOK, map[string]string{"status": "deleted", "id": id})
		return
	}
	s.render(w, http.StatusOK, "error.html", errorPage{
		page:    s.page("Deleted", false),
		Status:  "Deleted",
		Message: "The file is gone.",
	})
}

// mayDelete checks the presented secret against the object's delete token
// first, then against the token file.
func (s *Server) mayDelete(m *store.Meta, secret string) bool {
	if auth.EqualHash(m.DeleteHash, auth.HashSecret(secret)) {
		return true
	}
	if err := s.tokens.MaybeReload(); err != nil {
		s.log.Error("reloading token file", "err", err)
	}
	t := s.tokens.Lookup(secret)
	if t == nil {
		return false
	}
	return t.Admin || (m.Owner != "" && t.Name == m.Owner)
}